Update comments and test mix-blend-mode on pattern

The working group recently resolved that mix-blend-mode should not apply to never-rendered elements such as pattern, see: https://github.com/w3c/fxtf-drafts/issues/309. This patch updates the comment in LayoutObject::IsBlendingAllowed and adds a web platform test (all browsers should pass this already). This removes the TODO added in https://chromium-review.googlesource.com/c/chromium/src/+/1169624. Change-Id: Ie74fd48075ae377636cb3efe93dd2fa6896fc534 Reviewed-on: https://chromium-review.googlesource.com/c/1303954Reviewed-by: Fredrik Söderquist <fs@opera.com> Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org> Commit-Queue: Philip Rogers <pdr@chromium.org> Cr-Commit-Position: refs/heads/master@{#603379}

Update comments and test mix-blend-mode on pattern
The working group recently resolved that mix-blend-mode should not apply to never-rendered elements such as pattern, see: https://github.com/w3c/fxtf-drafts/issues/309. This patch updates the comment in LayoutObject::IsBlendingAllowed and adds a web platform test (all browsers should pass this already). This removes the TODO added in https://chromium-review.googlesource.com/c/chromium/src/+/1169624. Change-Id: Ie74fd48075ae377636cb3efe93dd2fa6896fc534 Reviewed-on: https://chromium-review.googlesource.com/c/1303954Reviewed-by: Fredrik Söderquist <fs@opera.com> Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org> Commit-Queue: Philip Rogers <pdr@chromium.org> Cr-Commit-Position: refs/heads/master@{#603379}
7467bb95 · Philip Rogers · Commit Bot · 0a3af5bc · 7467bb95 · 7467bb95
Commit 7467bb95 authored Oct 28, 2018 by Philip Rogers Committed by Commit Bot Oct 28, 2018
3 changed files
--- a/third_party/WebKit/LayoutTests/external/wpt/svg/render/reftests/filter-effects-on-pattern-ref.html
+++ b/third_party/WebKit/LayoutTests/external/wpt/svg/render/reftests/filter-effects-on-pattern-ref.html
+<!DOCTYPE html>
+<div>Expected: a solid green square.</div>
+<svg style="width: 200px; height: 200px; background: green;"></svg>
--- a/third_party/WebKit/LayoutTests/external/wpt/svg/render/reftests/filter-effects-on-pattern.html
+++ b/third_party/WebKit/LayoutTests/external/wpt/svg/render/reftests/filter-effects-on-pattern.html
+<!DOCTYPE html>
+<title>'mix-blend-mode' for &lt;svg:pattern&gt;</title>
+<link rel="help" href="https://www.w3.org/TR/SVG2/render.html#PaintersModel">
+<link rel="help" href="https://github.com/w3c/fxtf-drafts/issues/309">
+<link rel="match"  href="filter-effects-on-pattern-ref.html">
+<div>Expected: a solid green square.</div>
+<svg style="width: 200px; height: 200px; background: green;">
+  <defs>
+    <pattern id="pattern" x="0" y="0" width=".25" height=".25" style="mix-blend-mode: difference;">
+      <rect x="0" y="0" width="25" height="25" fill="green"/>
+    </pattern>
+  </defs>
+  <rect fill="url(#pattern)" width="200" height="200"/>
+</svg>
--- a/third_party/blink/renderer/core/layout/layout_object.h
+++ b/third_party/blink/renderer/core/layout/layout_object.h
@@ -749,8 +749,8 @@ class CORE_EXPORT LayoutObject : public ImageResourceObserver,
  bool IsBlendingAllowed() const {
    return !IsSVG() || IsSVGShape() || IsSVGImage() || IsSVGText() ||
           IsSVGInline() || IsSVGRoot() || IsSVGForeignObject() ||
-           // TODO(pdr): According to the current spec, blending should apply to
+           // Blending does not apply to non-renderable elements such as
-           // hidden containers (e.g. pattern).
+           // patterns (see: https://github.com/w3c/fxtf-drafts/issues/309).
           (IsSVGContainer() && !IsSVGHiddenContainer());
  }
  virtual bool HasNonIsolatedBlendingDescendants() const {